What would water and fire do to the Nazgul?

If the Nazgûl did fear water, wouldn't it have taken the longer to get to the Shire? Because if they did fear water, they would have to out of their way to cross the bridges ovey the Anduin and all the other rivers.

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"Over the land there lies a long shadow,
westward reaching wings of darkness.
The Tower trembles; to the tombs of kings
doom approaches. The Dead awaken;
for the hour has come for the oathbreakers:
at the Stone of Erech they shall stand again
and hear there a horn in the hills ringing.
Whose shall the horn be? Who shall call them
from the grey twilight, the forgotten people?
The heir of him to whom the oath they swore.
From the North shall he come, need shall drive him:
he shall pass the Door to the Paths of the Dead."